Woellner, C. et al. [10] proposed diagnostic guidelines for STAT3-deficient HIES in 2010, considering IgE > 1000 IU/mL, clinical features (recurrent pneumonia, newborn rash, pathologic bone fractures, characteristic face, and high palate), and lack of Th17 cells or a family history for definitive HIES, along with a DN heterozygous mutation in STAT3 as the definitive diagnosis of STAT3-HIES. Here, STAT3 is linked to pneumonia.